Many types of single-dose capsules containing a product in powder or granular form, or a finely shredded product, suitable for the preparation of beverages, are known from the prior art. In the description below reference will be made specifically to a capsule containing coffee powder, it being understood, however, that the present invention is likewise applicable also to products such as herbal teas, infusions, etc.
A capsule of this type is described for example in Italian patent IT 0001342663, in the name of the same applicant. Said patent describes a capsule with a substantially cylindrical outer structure made of polymer material where the top base and the bottom base are lined with a film suitable for being sealed on the top edge and bottom edge of the outer structure, respectively. Generally, the film consists of an aluminum foil or the like suitable for alimentary use.
The use of capsules results in numerous advantages, including the possibility of keeping a product packaged in a controlled atmosphere until the moment it is used. Moreover, by using capsules it is possible to stock a huge variety of products, without the risk of rapid deterioration of the open and unconsumed product.
For the same reasons, capsules are widely used not only in a domestic environment, but also in bars, both in specifically designed coffee machines and in professional coffee machines which were originally designed for producing coffee using loose powder.
With regard to professional coffee machines, the international patent application WO 2011/010338, in the name of the same applicant, describes an adaptor to be applied to a professional coffee machine so that a capsule (for example the capsule mentioned further above) may be used instead of a loose product. In one of the embodiments of the adaptor, a first device suitable for being positioned inside a removable filter-holder, designed to contain a capsule, and a second device which can be gripped, suitable for piercing the upper film of the capsule, are described.
Even though this device is widely used, it is not, however, without certain drawbacks.
A first drawback arises during piercing of the upper film of the capsule positioned inside the filter-holder. In some cases it has been noted that the capsule remains attached to the device for piercing the upper film, resulting in extraction of the capsule from the filter-holder.
A second drawback arises during the dispensing of products which have widely varying characteristics. For example, it has been noted that, in order to produce better coffee, numerous holes must be provided in the upper film, while for the production of other infusions, it is advisable to have few holes preferably arranged on the periphery of the upper film of the capsule, in order to enhance the properties of the shredded product contained inside the capsule.
A further drawback consists in the fact that, during piercing of a capsule inserted inside a filter-holder, the user with one hand grips the handle of the filter-holder, while with the other hand he/she acts on the capsule with the piercing device. It can therefore be easily understood that the direction in which the user uses his/her two hands is not the same, resulting in problems of stability during the piercing operation. In some cases, therefore, imprecise or irregular piercing of the capsule may occur.